N-thienylalkylacetanilides

ABSTRACT

WHEREIN R1 is lower alkyl; R2 is selected from the group consisting of hydrogen, lower alkyl and lower alkoxy; Y is selected from the group consisting of hydrogen, lower alkyl and halogen; R3 and R4 are independently selected from the group consisting of hydrogen and lower alkyl; n is the integer 1 or 2; and X is halogen. The compounds of the above description are useful as herbicides. This invention discloses new compounds of the formula

United States Patent [191 Richter et al.

[ Aug. 26, 1975 l N-THIENYLALKYLACETANILIDES [75] Inventors: Sidney B. Richter, Chicago; John Krenzer, Oak Park, both of III.

[73] Assignee: Velsicol Chemical Corporation,

Chicago, Ill.

[22] Filed: Nov. 4, 1974 [21] Appl. No.: 520,391

[52] US. Cl 260/329 AM; 71/90 [51] Int. Cl. C07D 333/00 [58] Field of Search 260/329 AM [56] References Cited UNITED STATES PATENTS 2,556,566 6/1951 Weston 260/329 2,629,720 2/1953 Kyrides 260/329 Primary Examiner-Bernard Helfin Assistant ExaminerA. Siegel Attorney, Agent, or FirmRobert J. Schwarz; Dietmar H. Olesch [5 7] ABSTRACT This invention discloses new compounds of the formula wherein R is lower alkyl; R is selected from the group consisting of hydrogen, lower alkyl and lower alkoxy; Y is selected from the group consisting of hy drogen, lower alkyl and halogen; R and R are independently selected from the group consisting of hydrogen and lower alkyl; n is the integer l or 2; and X is halogen. The compounds of the above description are useful as herbicides.

6 Claims, N0 Drawings I 2 N-THlENYLALKYLACETANILIDES wherein R and X are as heretofore described. This re- This invention relates to new compositions of matter action can be conveniently effected by combining a and more specifically relates to new compounds of the compound of formula II with a compound of formula formula Ill in an inert organic reaction medium and in the pres- 5 R l Z n N S c cs x Y l 3 2 O R R (I) wherein R' is lower alkyl; R" is selected from the group ence of an acid acceptor such as an alkali metal carconsisting of hydrogen. lower alkyl and lower alkoxy; bonate or bicarbonate. The compound of formula III Y is selected from the group consisting of hydrogen. can be added to a solution of the compound of formula lower alkyl and halogen; R" and R are independently I! which also contains the acid acceptor and a small selected from the group consisting of hydrogen and amount of water at a temperature of from about 0 to lower alkyl; n is the integer l or 2; and X is halogen. about 10C. After the addition is completed the reac- 'lhe term lower as used herein designates a straight tion mixture can be stirred for a period of about 1 hour or branched carbon chain of up to 4 carbon atoms. 7; to ensure completion of the reaction. After this time In a preferred embodiment of the present invention the reaction mixture can be washed with water to re- Y. R and R are hydrogen and X is chlorine or hromove inorganic salts and then stripped of solvent to i yield the desired product. This product can be used as The compounds ofthe present invention are useful as Such 11 be f r hfl P rified by Conventional means. herbicides and are particularly useful for controlling 3n the growth of grassy weeds. The compounds of formula II can be prepared by hy- The compounds of the present invention an PI drogenating the nitrogen-carbon double bond of a pared from a compound of the formula compound of the formula R (II) .N cs (cl-I Y A V I I (all I herein R R: Y. R and n are as heretofore dewherein m is the integer (l or I and R. R- and R are scribed. by reaction with an cx-haloalkanoyl chloride of as heretofore described. with lithium aluminum hythe formula dride. This reaction can be effected by adding the lithium aluminum hydride to a solution of the compound 0 M of formula IV in an organic solvent such as ether and ll heating the resulting reaction medium at temperatures l 4 x of up to the reflux temperature ofthe mixture fora per- R illh iod of from [5 minutes to about 6 hours. After this time iethanol and water can be added to the reaction mixurc followed by filtration of the mixture to remove inrganic salts. The reaction mixture can then be washed rith water or with aqueous sodium carbonate. dried nd stripped of solvent to yield the desired product.

The above hydrogenation can also be effected by utizing hydrogen gas in the presence of an appropriate atalyst such as platinum and paladium. This reaction an be carried out at ambient temperatures and at presures ranging from atmospheric pressure to about l()() lounds per square inch.

The compounds of formula TV, when not available. an be prepared by reacting about equimolar amounts If a compound of the formula wherein R. R and Y are as heretofore described. and a compound of the formula one (cl-1 3 Z-thiophenecarboxaldehydc. 4-methyl-Z-thiophenecar boxaldehyde. 3-ethyl-Z-thiophenecarlmxaldehyde. 4- isopropyl-Z-thiophenecarboxaldehyde. 4-hexyl-Z-thiophcnecarboxaldehyde. u-(4-methylthien-2- yl )acetaldchyde. u-t 3-ethylthicn-2-y l )acctaldehyde and the like.

Exemplary compounds of formula V are 2- methylaniline. Z-ethylaniline, Z-propylaniline. 2-

butylaniline. 2,6-dimethylaniline. 2.6-diethylaniline. 2,o-dipropylaniline, 2.6dibutylaniline. Z-methyl-omethoxyaniline. lethyl-fi-methoxyaniline, Z-butyl-bbutoxyaniline. Z-methyl-4-chloroaniline, 2-methyl-4- bromoaniline, 2-methyl-4-fluoroaniline. 2.6-dimethyl- 4-chloroaniline, 2,4,6-trimethylaniline and the like.

Exemplary compounds of formula III useful for preparing the compounds of the present invention are a-chloroacetyl chloride, a-bromoacetyl chloride. a-chloropropionyl chloride. a-bromopropionyl chloride. a-chlorobutanoyl chloride. a-chloropentanoyl chloride and the like.

The manner in which the compounds of the present invention can be prepared is more specifically illustrated in the following examples.

EXAMPLE I Preparation of N-Z-Thenylidine-2.6-din1ethylaniline Lh-dimcthylaniline (36 grams). 2-thiophenecarboxaldehyde (33 grams), and toluene ml) were charged into a glass reaction vessel equipped with a mechanical stirrer. thermometer and reflux condenser. The reaction mixture was then heated at reflux, with stirring for a period of about 48 hours. After this time the reaction mixture is distilled to yield the desired product N2-thenylidine-Z.h-dimethylaniline having a boiling point of 128 to l29C at 0.6 mm of Hg pressure.

EXAMPLE 2 Preparation of N-( Z-Thienylmcthylcne )-2.6dimethylaniline N-Z-Thenylidine-lh-dimethylaniline (36 grams), ether (400 ml) and lithium aluminum hydride (3.0 grams) were charged into a glass reaction vessel equipped with a mechanical stirrer, thermometer and reflux condenser. The resulting mixture was stirred and heated at reflux for a period of about 4 hours. After this time methanol 100 ml) and water (100 ml) were added and the resulting mixture was filtered. The filtratc was then washed with aqueous sodium bicarbonate and was dried over anhydrous magnesium sulfate. The dried solution is stripped of solvent to yield the desired product N( 'l-thienylmethylene 1 2,6- dimethylaniline having a boiling point of lZl to [23C at (m mm of Hg pressure.

EXAMPLE 3 Preparation of N-( Z-Thicnylmcthylene )-2.6-dimethyl-uchloroacetanilide N-Z-Thicnylmethy lene )-2.h-dimethylaniline 15.0 grams). sodium bicarbonate 15 grams). pentane (30 ml) and water Hit) ml) were charged into a glass reaction vessel equipped with a thermometer and mechanical stirrer. The mixture was cooled to about 0C and chloroacetyl chloride (81) grams) was incrementally added thereto. After the addition was completed the reaction mixture was stirred for a period of about 1 hour and allowed to warm up to room temperature. The solid product which formed was then recovered by filtration and was recrystalliled from heptane to yield the desired product N-(2-thienylmethylene]-2.6- dimethyl-a-chloroacetanilide having a melting point of 107 to 109C.

EXAMPLE 4 Preparation of N-Z-Thenylidine-Z.fi-diethylaniline 2.6-Diethylaniline grams). Z-thiophenecarhoxaldehyde l 1 grams) and toluene (50 ml) were charged into a glass reaction vessel equipped with a mechanical stirrer. thermometer and reflux condenser. The reaction mixture was then heated at reflux with stirring for a period of about 48 hours. After this time the reaction mixture was distilled to yield the desired product N-2- thenylidine-2.6-diethylaniline having a boiling point of 132 to 133C at 0.6 mm of Hg pressure.

EXAMPLE 5 Preparation of N-( Z-Thienylmethylene J2.6-diethy1aniline 2Thenylidine-Zb-diethylaniline (23.2 grams). ether (300 ml] and lithium aluminum hydride (2.0 grams) were charged into a glass reaction vessel equipped with a mechanical stirrer and thermometer. The resulting mixture was stirred at ambient temperature for a period of about 16 hours. After this time methanol (10 ml) and water 10 ml) were added to the reaction mixture with stirring. The mixture was then filtered. dried over anhydrous magnesium sulfate and distilled under reduced pressure to yield the desired product N-(2- thienylmethylene)-2.fi-diethylaniline.

EXAMPLE 6 EXAMPLE 7 Preparation of N-Z-Theny lidine 2-methyl-5chloroaniline Z-Methylfi-chloroaniline [0.3 mole). Z-thiophenecarboxaldehyde (11.3 mol) and ben7ene 100 ml) are charged into a glass reaction vessel equipped with a mechanical stirrer. thermometer and reflux con denser. The reaction mixture is then heated at reflux. with stirring for a period of about 72 hours. After this time the reaction mixture is distilled to yield the desired product N-Z-thenylidine-Z-methyl 5-chloroanilinc.

EXAMPLE 8 Preparation of N-( Z-Thienylmethylene )Q-methyLS'chloroaniline N-Z-Thenylidine-Z-methyl-S-chloroaniline (0.1 mole) dissolved in ether ml) is charged into a glass reaction vessel equipped with a mechanical stirrer. thermometer and reflux condenser. Lithium aluminum hydride (2 grams) is added to the flask and the resulting mixture stirred at room temperature for a period of about 1 hour. The reaction mixture is then heated at reflux. with stirring. for an additional hour. After this time methanol 10 ml) and water 10 ml) are added and the resulting mixture is filtered. The filtrate is then washed with water and is dried over anhydrous magnesium sulfate. The dried solution is stripped of solvent to yield the desired product N-( 2- thienylmethylene)-Z-methyl-S-chloroaniline.

EXAMPLE 9 Preparation of N-( Z-Thienymethylene )-2-methyl-5-adichloroacetanilide N-( Z-Thienylmethylene )-2-meth vl-5-chloroaniline (0.05 mole). sodium bicarbonate 10 grams). dioxane (25 ml) and water (6 ml) are charged into a glass reaction vessel equipped with a thermometer and mechanical stirrer. The mixture is cooled to about 0C and chloroacetyl chloride (0.05 mole) is incrementally added thereto. After the addition is completed the reaction mixture is stirred for a period of about 1 hour and allowed to warm up to room temperature. After this time ether 100 ml) is added to the mixture with stirring. The resulting mixture is then washed with water and dried over anhydrous magnesium sulfate. The dried solution is stripped of solvent to yield the desired product N4 Z-thienylmethylene )-2-methyl'5-o1- dichloroacetanilide.

EXAMPLE 10 Preparation of N-Z-Thenylidine-Z-methylaniline Z-Methylaniline (0.3 mole). 2-thiophenccarboxaIdehyde (0.3 mole) and benzene (100 ml) are charged into a glass reaction vessel equipped with a mechanical stirrer. thermometer and reflux condenser. The reaction mixture is then heated at reflux. with stirring, for a period of about 36 hours. After this time the reaction mixture is distilled to yield the desired product N-2- thenylidine-Z-methylaniline.

EXAMPLE 1] Preparation of N-( 2-lhienylmethylene )-2-methylaniline N-2-Thenylidine-Z-mcthylaniline (0.1 mole) dissolved in ether 100 ml) is charged into a glass reaction vessel equipped with a mechanical stirrer. thermometer and reflux condenser. Lithium aluminum hydride (2 grams) is added to the flask and the resulting mixture stirred at room temperature for a period of about 1 hour. The reaction mixture is then heated at reflux. with stirring. for an additional hour. After this time methanol ll) ml) and water 10 ml) are added and the resulting mixture is filtered. The filtrate is then washed with water and is dried over anhydrous magnesium sulfate. The dried solution is stripped of solvent to yield he desired N-( 2thienylmethylene )-2- nethylaniline.

product EXAMPLE 12 N-(Z-Thienylmethylene)2-methylaniline (0.05 nole), sodium bicarbonate (10 grams). dioxane (30 nl) and water ml) are charged into a glass reaction essel equipped with a thermometer and mechanical tirrer. The mixture is cooled to about 0C and a-chloopropionyl chloride (0.05 mole) is incrementally .dded thereto. After the addition is completed the re- .ction mixture is stirred for a period of about I hour .nd allowed to warm up to room temperature. After his time ether (l00 ml) is added to the mixture with tirring. The resulting mixture is then washed with rater and dried over anhydrous magnesium sulfate. he dried solution is stripped of solvent to yield the deired product N(2-thienylmethylene)-N-ahloropropionyl-2-methylaniline.

EXAMPLE l3 Preparation of N-( 2-Thienylethyledene )-2,6-diethylaniline 2,6-Diethylaniline (0.3 mole), a-thien-2- 'lacetaldehyde (0.3 mole) and benzene (120 ml) are 'harged into a glass reaction vessel equipped with a nechanical stirrer, thermometer and reflux condenser. The reaction mixture is then heated at reflux, with stiring. for a period of about 72 hours. After this time the eaction mixture is distilled to yield the desired product J-(Z-thienylethyledene)-2,6-diethylaniline.

EXAMPLE 14 Preparation of N-( 2-Thienylethyl)-2,6-diethylaniline N-( 2-Thienylethyledene)-2,6-diethylaniline (0. l nole) dissolved in ether (100 ml) is charged into a ;lass reaction vessel equipped with a mechanical stirer, thermometer and reflux condenser. Lithium alumiium hydride (2 grams) is added to the flask and the reulting mixture stirred at room temperature for a per- 0d of about hour. The reaction mixture is then ieated at reflux, with stirring, for an additional hour. \fter this time methanol ml) and water l0 ml) are .dded and the resulting mixture is filtered. The filtrate then washed with water and is dried over anhydrous nagnesium sulfate. The dried solution is stripped of olvent to yield the desired product N-( Z-thienylethyl 1,6-diethylaniline.

EXAMPLE l5 Preparation of -l-( Z-Thienylethylene )-2,(a-diethyl-a-bromoacetanilide N-( Z-Thienylethyl )-2,6-diethylaniline (0.1 mole so ium bicarbonate ([0 grams), dioxane ml) and later (6 ml) are charged into a glass reaction vessel quipped with a thermometer and mechanical stirrer. he mixture is cooled to about 0C and bromoacetyl hloride ((1.05 mole) is incrementally added thereto. \fter the addition is completed the reaction mixture is tirred for a period of about I hour and allowed to /arm up to room temperature. After this time ether I00 ml) is added to the mixture with stirring. The reulting mixture is then washed with water and dried over anhydrous magnesium sulfate. The dried solution is stripped of solvent to yield the desired product N-( 2- thienylethylene )-2,o-diethyl-a-bromoacetanilide.

Additional exemplary compounds which can be prepared according to the procedures of the foregoing examples are N-(Z-thienylmethylene)-2-methyl-4-chloroa-chloroacetanilide, N-(Z-thienylmethylene)-2-ethyl- 4-bromo-a-chloroacetanilide, N-( 2-thienylmethylene 2-propyl-4-fluoro-oz-chloroacetanilide, N-( 2- thienylmethylene )-2-hexyl-4-iodoa-chloroacetanilide, N-(4-methyl-2-thienylmethylene)-2,6-dimethyl-ozchloroacetanilide, N-( 3-ethyl-2-thienylmethylene )-2,6- cliethyl-4-chloro-oz-chloroacetanilide, N-(4-pr0pyl-2- thienylmethylene)-2-methyl-6-methoxy-achloroacetanilide, N-( 2-thienylmethylene)-2-methyl-6- ethoxy-a-chloroacetanilide, N-( 2-thienylmethylene )-2- methyl-o-propoxy-a-chloroacetanilide, N-( 2- thienylmethylene)-2-methyl-6-hexyloxy-achloroacetanilide, N-( Z-thienylmethylene)-2,6-diethyla-bromoacetanilide, N-(2-thienylmethylene)-2,6- dimethyl-4-fluoro-o:-chloropropionanilide, N-( 2- thienylmethylene)-2,4,6-trimethyl-achlorobutyranilide, N-( Z-thienylmethylene)-2,4,6- triethyl-a-bromopropion anilide, N-( 2- thienylmethylene)-N-oz-chloropentanoyl-2,6- diethylaniline, N-( Z-thienylmethylene )-N-achlorohexanoyl-2,6-diethylaniline, N-(2- thienylmethylene)-N-a-bromoheptanoyl-2,6- diethylaniline and the like.

For practical use as herbicides the compounds of this invention are generally incorporated into herbicidal compositions which comprise an inert carrier and a herbicidally toxic amount of such a compound. Such herbicidal compositions, which can also be called formulations, enable the active compound to be applied conveniently to the site of the weed infestation in any desired quantity. These compositions can be solids such as dusts, granules, or Wettable powders; or they can be liquids such as solutions, aerosols, or emulsifiable concentrates.

For example, dusts can be prepared by grinding and blending the active compound with a solid inert carrier such as the tales, clays, silicas, pyrophyllite, and the like. Granular formulations can be prepared by impregnating the compound, usually dissolved in a suitable solvent, onto and into granulated carriers such as the attapulgites or the vermiculites, usually of a particle size range of from about 0.3 to 1.5 mm. Wettable powders, which can be dispersed in water or oil to any desired concentration of the active compound, can be prepared by incorporating wetting agents into concentrated dust compositions.

In some cases the active compounds are sufficiently soluble in common organic solvents such as kerosene or xylene so that they can be used directly as solutions in these solvents. Frequently, solutions of herbicides can be dispersed under super-atmospheric pressure as aerosols. However, preferred liquid herbicidal compositions are cmulsiliable concentrates, which comprise an active compound according to this invention and as the inert carrier, a solvent and an emulsifier. Such emulsifiable concentrates can be extended with water and/or oil to any desired concentration of active compound for application as sprays to the site of the weed infestation. The emulsifiers most commonly used in these concentrates are nonionic or mixtures of nonionic with anionic surface-active agents. With the use EXAMPLE l6 Preparation of a Dust Product of Example 3 Powdered Talc The above ingredients are mixed in a mechanical grinder-blender and are ground until a homogeneous, free-flowing dust of the desired particle size is obtained. This dust is suitable for direct application to the site of the weed infestation.

The compounds of this invention can be applied as herbicides in any manner recognized by the art. One method for the control of weeds comprises contacting the locus of said weeds with a herbicidal composition comprising an inert carrier and as an essential active ingredient, in a quantity which is herbicidally toxic to said weeds, a compound of the present invention. The concentration of the new compounds of this invention in the herbicidal compositions will vary greatly with the type of formulation and the purpose for which it is designed, but generally the herbicidal compositions will comprise from about 0.05 to about 95 percent by weight of the active compounds of this invention. In a preferred embodiment of this invention, the herbicidal compositions will comprise from about 5 to about 75 percent by weight of the active compound. The compositions can also comprise such additional substances as other pesticides, such as insecticides. nematocides, fungicides, and the like; stabilizers, spreaders, deactivators, adhesives, stickers, fertilizers, activators, synergists, and the like.

The compounds of the present invention are also useful when combined with other herbicides and/or defoliants, dessicants, growth inhibitors, and the like in the herbicidal compositions heretofore described. These other materials can comprise from about 5 to about 95 percent of the active ingredients in the herbicidal compositions. Use of combinations of these other herbicides and/or defolia nts, dessicants, etc. with the compounds of the present invention provide herbicidal compositions which are more effective in controlling weeds and often provide results unattainable with separate compositions of the individual herbicides. The other herbicides, defoliants, dessicants and plant growth inhibitors, with which the compounds of this invention can be used in the herbicidal compositions to control weeds, can include chlorophenoxy herbicides such as 2.4-D, 2.4,5-T, MCPA, MCPB, 4(2,4-DB), 2,4- DEB, 4-CPB. 4-CPA, 4-CPP, 2,4,5-TB, 2,4,5-TES, 3,4- DA, silvex and the like; carbamate herbicides such as IPC, CIPC, swep, barban, BCPC, CEPC, CPPC, and the like; thiocarbamate and dithiocarbamate herbicides such as CDEC, metham sodium, EPTC, diallate, PEBC, perbulate, vernolate and the like; substituted urea herbicides such as norea, siduron, dichloral urea, chloroxuron, cycluron, fenuron. monuron, monuron TCA, diuron, linuron. monolinuron. neburon, buturon. trimeturon and the like; symmetrical tria7ine herbicides such as simazine, chlorazine, atraone, desmetryne, noraline,

ipazine, prometryn, atazinc, trietazine, simetone,

prometone. propazine, ametryne and the like; chloroacetamide herbicides such as 4- (chloroacety)morpholine, 1-(chloroacetyl)piperidine and the like; chlorinated aliphatic acid herbicides such as TCA, dalapon, 2,3-dichloropropionic acid, 2,2,3 TPA and the like; chlorinated benzoic acid and phenylacetic acid herbicides such as 2,3,6-TBA, 2,3,5,6-TBA, dicamba, tricamba, amiben, fenac, PBA, 2-methoxy- 3,6-dichlorophenylacetic acid, 3-methoxy- 2,6- dichlorophenylacetic acid, 2-methoxy-3,5,o-trichlorophenylacetic acid, 2,4-dichloro-3-nitrobenzoic acid and the like; and such compounds as aminotriazole, maleic hydrazide, phenyl mercuric acetate, endothal, biuret, technical chlordane, dimethyl 2,3,5,6-tetrachloroterephthalate, diquat, erbon, DNC, DNBP, dichlobenil, DPA, diphenamid, dipropalin, trifluralin, solan, dicryl, merphos, DMPA, DSMA, MSMA, potassium azide, acrolein, benefin, bensulide, AMS, bromacil, 2-( 3,4-dichlorophenyl)-4-methyll ,2,4- oxadiazolidine-3,5-dione, bromoxynil, cacodylic acid, CMA, CPMF, cypromid, DCB, DCPA, dichlone, diphenatril, DMTI, DNAP, EBEP, EXD, HCA, ioxynil, IPX, isocil, potassium cyanate, MAA, MAMA, MCPES, MCPP, MH, molinate, NPA, OCH, paraquat, PCP, picloram, DPA, PCA, pyrichlor, sesone, terbacil, terbutol, TCBA, brominil, CI -50144, H-l76- l, H-732, M2901 planavin, sodium tetraborate, calcium cyanamid, DEF, ethyl xanthogen disulfide, sindone, sindone B, propanil and the like.

Such herbicides can also be used in the methods and compositions of this invention in the form of their salts, esters, amides, and other derivatives whenever applicable to the particular parent compounds.

Weeds are undesirable plants growing where they are not wanted, having no economic value and interfering with the production of cultivated crops, with the growing of ornamental plants, or with the welfare of livestock. Many types of weeds are known, including annuals such as pigweed, lambsquarters, foxtail, crabgrass, wild mustard, field pennycress, ryegrass, goose grass, chickweed, wild oats, velvetleaf, purslane, barnyardgrass, smartweed, knotweed, cocklebur, wild buckwheat, kochia, medic, corn cockle, ragweed, sowthis tle, coffeeweed, croton, cuphea, dodder, fumitory, groundsel, hemp nettle, knawel, spurge, spurry, emex, jungle rice, pondweed, dog fennel, carpetweed, morningglory, bedstraw, ducksalad, naiad, cheatgrass, fall panicum, jimsonweed, witchgrass, switchgrass, watergrass, teaweed, wild turnip and sprangletop; biennials such as wild carrot, matricaria, wild barley, campion, chamomile, burdock, mullein, roundleaved mallow, bull thistle, houndsdongue, moth mullein and purple star thistle; or perennials such as white cockle, perennial ryegrass, quackgrass, Johnson grass, Canada thistle, hedge bindweed, Bermuda grass, sheep sorrel, curly dock, nutgrass, field chickweed, dandelion, campanula, field bindweed, Russian knapweed, mesquite, toadflax, yarrow, aster, gromwell, horsetail, ironweed, sesbania, bulrush, cattail, wintercress, horsenettle, nutsedge, milkweed and sicklepod.

Similarly, such weeds can be classified as broadleaf or grassy weeds. It is economically desirable to control the growth of such weeds without damaging beneficial plants or livestock.

The new compounds of this invention are particularly valuable for weed control because they are toxic to many species and groups of weeds while they are relavely non-toxic to many beneficial plants. The exact mount of compound required will depend on a variety f factors, including the hardiness of the particular 'eed species. weather. type of soil, method of applicaon, the kind of beneficial plants in the same area, and 1e like. Thus, while the application of up to only about ne or two ounces of active compound per acre may be iflicient for good control of a light infestation of eeds growing under adverse conditions, the applicaon of ten pounds or more of an active compound per :re may be required for good control of a dense infesltion of hardly perennial weeds growing under favorale conditions.

The herbicidal toxicity of the new compounds of this |vention can be illustrated by many of the established :sting techniques known to the art, such as preand est-emergence testing.

The herbicidal activity of the compounds of this inzntion was demonstrated by experiments carried out )r the pre-emergence control of a variety of weeds. in iese experiments small plastic greenhouse pots filled ith dry soil were seeded with the various weed seeds. wenty-four hours or less after seeding the pots were rayed with water until the soil was wet and the test ampounds formulated as aqueous emulsions of aceme solutions containing emulsifiers were sprayed at ie indicated concentrations on the surface of the soil. After spraying, the soil containers were placed in the reenhouse and provided with supplementary heat as :quired and daily or more frequent watering. The Iants were maintained under these conditions for a eriod of from 15 to 2l days, at which time the condion of the plants and the degree of injury to the plants as rated on a scale of from 0 to l(), as follows: 0 no jury. l,2 =slight injury, 3,4 moderate injury, 5,6 .oderately severe injury, 7,8,9 severe injury and 10 death. The effectiveness of these compounds is demistrated by the following data:

The herbicidal activity of the compounds of this invention was also demonstrated by experiments carried out for the post-emergence control of a variety of weeds. In these experiments the compounds to be tested were formulated as aqueous emulsions and sprayed at the indicated dosage on the foliage of the weeds that have attained a prescribed size. After spraying the plants were placed in a greenhouse and watered daily or more frequently. Water was not applied to the foliage of the treated plants. The severity of the injury was determined l0 to l5 days after treatment and was rated on the scale of from O to 10 heretofore described. The effectiveness of these compounds is demonstrated by the following data:

TABLE II lnjuury Rating Product of Product of Example 3 Example 6 Concentration (lbs/acre) l0 2 Weed Species We claim: I. A compound of the formula wherein R is lower alkyl, R is selected from the group consisting of hydrogen, lower alkyl and lower alkoxy; Y is selected from the group consisting of hydrogen, lower alkyl and halogen; R" and R are independently selected from the group consisting of hydrogen and lower alkyl; :1 is the integer l or 2; and X is halogen.

2. The compound of claim I, N-( 2- thienylmethylene1-2,6-dirnethyl-a-chloroacetanilide.

3. The compound of claim l, N-( 2 thienylmethylene )-2,o-diethyl-a-chloroacetanilide.

4. The compound of claim l N-( 2- thienylmethylene )-2-methyl-5-a-dichloroacetanilide.

5. The compound of claim 1. N-( 2- thienylmethylcne )-Na-chloropropionyl-Z- methylaniline.

6. The compound of claim 1. N-( 2-thienylethylene)- 2,6-diethyl-u-hromoacctanilidc. 

1. A COMPOUND OF THE FORMULA
 2. The compound of claim 1, N-(2-thienylmethylene)-2,6-dimethyl-Alpha -chloroacetanilide.
 3. The compound of claim 1, N-(2-thienylmethylene)-2,6-diethyl-Alpha -chloroacetanilide.
 4. The compound of claim 1, N-(2-thienylmethylene)-2-methyl-5-Alpha -dichloroacetanilide.
 5. The compound of claim 1, N-(2-thienylmethylene)-N- Alpha -chloropropionyl-2-methylaniline.
 6. The compound of claim 1, N-(2-thienylethylene)-2,6-diethyl-Alpha -bromoacetanilide. 